As conventional wild-type firefly luciferases, those derived from Genji firefly (Luciola cruciata), Heike firefly (Luciola lateralis), North American firefly (Photinus pyralis), East European firefly (Luciola mingrelica), Tuchi firefly (Lampyris noctiluca) etc. are known.
Further, mutant-type luciferases (with mutations in thermostability, luminescent color etc.) have also been obtained from these wild-type firefly luciferases as the source.
Improvement of the catalytic efficiency and stability of this enzyme by mutating it is very important. This is because the improvement of catalytic efficiency leads to a reduction in the enzyme used while the improvement of stability makes the enzyme usable under reaction conditions which the wild-type enzyme could not be used.
However, none of such luciferases excellent in stability such as thermostability etc. and with high catalytic efficiency have been reported until now.